The Collaborative International Dictionary of English v.0.48:

Smack \Smack\, v. t.
   1. To kiss with a sharp noise; to buss.
      [1913 Webster]

   2. To open, as the lips, with an inarticulate sound made by a
      quick compression and separation of the parts of the
      mouth; to make a noise with, as the lips, by separating
      them in the act of kissing or after tasting.
      [1913 Webster]

            Drinking off the cup, and smacking his lips with an
            air of ineffable relish.              --Sir W.
                                                  Scott.
      [1913 Webster]

   3. To make a sharp noise by striking; to crack; as, to smack
      a whip. "She smacks the silken thong." --Young.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Smack \Smack\, adv.
   As if with a smack or slap. [Colloq.]
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Smack \Smack\, v. i. [imp. & p. p. Smacked; p. pr. & vb. n.
   Smacking.] [OE. smaken to taste, have a taste, -- from the
   noun; cf. AS. smecan taste; akin to D. smaken, G. schmecken,
   OHG. smechen to taste, smach?n to have a taste (and, derived
   from the same source, G. schmatzen to smack the lips, to kiss
   with a sharp noise, MHG. smatzen, smackzeen), Icel. smakka to
   taste, Sw. smaka, Dan. smage. See 2d Smack, n.]
   1. To have a smack; to be tinctured with any particular
      taste.
      [1913 Webster]

   2. To have or exhibit and indication or suggestion of the
      presence of any character or quality; to have a taste, or
      flavor; -- used with of; as, a remark smacking of
      contempt.
      [1913 Webster + PJC]

            All sects, all ages, smack of this vice. --Shak.
      [1913 Webster]

   3. To kiss with a close compression of the lips, so as to
      make a sound when they separate; to kiss with a sharp
      noise; to buss.
      [1913 Webster]

   4. To make a noise by the separation of the lips after
      tasting anything.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Smack \Smack\, n. [D. smak; akin to LG. smack, smak, Dan.
   smakke, G. schmacke, F. semaque.] (Naut.)
   A small sailing vessel, commonly rigged as a sloop, used
   chiefly in the coasting and fishing trade.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Smack \Smack\, n.
   Same as heroin; -- a slang term. [slang]
   [PJC]

The Collaborative International Dictionary of English v.0.48:

Smack \Smack\, n. [OE. smak, AS. ssm?c taste, savor; akin to D.
   smaak, G. geschmack, OHG. smac; cf. Lith. smagus pleasant.
   Cf. Smack, v. i.]
   1. Taste or flavor, esp. a slight taste or flavor; savor;
      tincture; as, a smack of bitter in the medicine. Also used
      figuratively.
      [1913 Webster]

            So quickly they have taken a smack in covetousness.
                                                  --Robynson
                                                  (More's
                                                  Utopia).
      [1913 Webster]

            They felt the smack of this world.    --Latimer.
      [1913 Webster]

   2. A small quantity; a taste. --Dryden.
      [1913 Webster]

   3. A loud kiss; a buss. "A clamorous smack." --Shak.
      [1913 Webster]

   4. A quick, sharp noise, as of the lips when suddenly
      separated, or of a whip.
      [1913 Webster]

   5. A quick, smart blow; a slap. --Johnson.
      [1913 Webster]

WordNet (r) 3.0 (2006):

smack
    adv 1: directly; "he ran bang into the pole"; "ran slap into
           her" [syn: bang, slap, slapdash, smack, bolt]
    n 1: a blow from a flat object (as an open hand) [syn: slap,
         smack]
    2: the taste experience when a savoury condiment is taken into
       the mouth [syn: relish, flavor, flavour, sapidity,
       savor, savour, smack, nip, tang]
    3: a sailing ship (usually rigged like a sloop or cutter) used
       in fishing and sailing along the coast
    4: street names for heroin [syn: big H, hell dust, nose
       drops, smack, thunder, skag, scag]
    5: an enthusiastic kiss [syn: smack, smooch]
    6: the act of smacking something; a blow delivered with an open
       hand [syn: smack, smacking, slap]
    v 1: deliver a hard blow to; "The teacher smacked the student
         who had misbehaved" [syn: smack, thwack]
    2: have an element suggestive (of something); "his speeches
       smacked of racism"; "this passage smells of plagiarism" [syn:
       smack, reek, smell]
    3: have a distinctive or characteristic taste; "This tastes of
       nutmeg" [syn: smack, taste]
    4: kiss lightly [syn: smack, peck]
    5: press (the lips) together and open (the lips) noisily, as in
       eating